1. Field of the Invention
The invention relates to and has among its objects the provision of a novel method for removing the outer waxy layer from papaya.
2. Description of the Prior Art
Papaya (Carica papaya) is a tropical plant, the fruit of which has an outer waxy layer, a thin skin (epidermal) layer beneath the waxy layer, a thick fleshy edible inner portion and a central seed-containing cavity. The outer waxy layer is composed of cutin, suberin and waxes and is a valuable source of these materials and particularly is a good natural source of cutin. Cutin is an insoluble, water-impermeable complex aggregate of waxes, fatty acids, higher alcohols and resinous material. It is the structural component of plant cuticle and is important in the prevention of the entry of pathogens into plants. In plant research, cutin is valuable as a substrate in the study of cutinase, an extracellular enzyme produced by plant pathogenic fungi which digests cutin thus allowing the fungi to attack and destroy the fruit. Currently, no commercial source of cutin exists because of the intensity of labor to isolate it.
Papayas are a good source of cutin. At present, the outer waxy, cutin-containing layer is removed from the flesh by immersing or rinsing the fruit in organic solvents such as chloroform-methanol and chloroform-ethanol at elevated temperatures or by freezing the fruit followed by immersion in hot (60.degree. C.) water and mechanical scraping of the outer surface of the fruit. The former method has the disadvantage of using hot solvents while the latter is labor intensive.